1. Technical Field
The invention relates to a disk drive device including a hub on which a recording disk is to be placed.
2. Related Art
In recent years, in a disk drive device such as a HDD, stiffness of a bearing is enhanced by providing a fluid dynamic bearing unit. The disk drive device having the fluid dynamic bearing unit is mounted in a small portable device in some cases. It is desired that a portable device be further reduced in thickness and weight. It is also desired that the disk drive device be further reduced in thickness and weight.
For example, JP-A-2007-198555 discloses a disk drive device having a fluid dynamic bearing unit in which a width of a first radial dynamic pressure groove in its axial direction is narrower than that of a second radial dynamic pressure groove in its axial direction.